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Any noticeable problems with the abs?
Going by past experiences I would guess it needs hydraulic control unit, most common cause is sticking isolation valves internal to unit, & cannot be serviced seperately. If you buy oem part from dealer it should come with fluid in unit, so you ca bleed system without ngs, or breaker box. But thats just a guess since I have not tested it. |
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Fuse/power to the pump?
Connections with all wheel speed sensors. Sensors themselves. What does the brake fluid look like? |
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Any noticeable problems with the abs? Going by past experiences I would guess it needs hydraulic control unit, most common cause is sticking isolation valves internal to unit, & cannot be serviced seperately. If you buy oem part from dealer it should come with fluid in unit, so you ca bleed system without ngs, or breaker box. But thats just a guess since I have not tested it. A general visual and mechanical inspection of the service brakes and ABS shows no obvious faults. You've got a multimeter and a wiring diagram, where do you start? |
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Fuse/power to the pump? You've verified that there is 12V at the pump motor. Connections with all wheel speed sensors. Sensors themselves. What does the brake fluid look like? A general visual inspection of the service brakes and ABS shows no obvious faults. |
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Fuck diagnosing the truck, I do that all week.
Lets see your I tunes list |
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I always start with the simplest explanation , the fuses , then I check the pump to see if it's actually working , work backward from there .
Is there a maintenence switch in the circut ? I know there was a 3 position switch on one car I worked on , the light would come on at certain intervals and wouldn't go out till the mechanic (me) inspected the system and flipped the switch hidden up under the dash . older BMW's had a little rig the mechanic had to reset the computer with . Anything like that going on here perhaps ? |
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I always start with the simplest explanation , the fuses , then I check the pump to see if it's actually working , work backward from there . Is there a maintenence switch in the circut ? I know there was a 3 position switch on one car I worked on , the light would come on at certain intervals and wouldn't go out till the mechanic (me) inspected the system and flipped the switch hidden up under the dash . older BMW's had a little rig the mechanic had to reset the computer with . Anything like that going on here perhaps ? Okay. You checked and verified, fuses 6 and 28 in the battery junction box are not open and there is power at them, likewise with fuses 11 and 14 at the central junction box. In the scan tool, there is a test called active commands, where we can use the scan tool to command the ABS pump on. Doing this, the pump does not run. There's no switches or electrical trickery here either. |
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I'm tired, and I've been drinking. Analytical skills will suffer. Tag for later.
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Fuck diagnosing the truck, I do that all week. Lets see your I tunes list It's 2600+ songs long. |
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I'm tired, and I've been drinking. Analytical skills will suffer. Tag for later. I've got others I can think of for later. It's easier for me just to use wiring diagrams than taking recordings and stuff with the scan tool. |
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You've got a multimeter and a wiring diagram, where do you start?[/quote] In my box there is more than a multimeter. I would get out the scaner and the scope and go from there. |
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Let me rephrase - you can diagnose and fix this concern with a wiring diagram and a multimeter (and maybe one more tool, one you'd have to make yourself with about $2 worth of materials).
ETA - Any Ford techs who've dealt with Ford technical assistance probably knows what tool I'm talking about. |
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Are you a tech, or you just looking for advise? I'm a tech. It originated a while back during a spirited thread, where some folks deemed that working on cars was a piece of cake, and no tech was worth more than like ten bucks an hour or whatever, which I disagree with, so I figure I'd put some stuff together from my daily routine and let other guys walk through and find the problem. |
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What is the motor's resistance/impedence, disconnected from the ABS control unit?
I believe the motor may be at fault. |
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Are you a tech, or you just looking for advise? I'm a tech. It originated a while back during a spirited thread, where some folks deemed that working on cars was a piece of cake, and no tech was worth more than like ten bucks an hour or whatever, which I disagree with, so I figure I'd put some stuff together from my daily routine and let other guys walk through and find the problem. You are Dr. Greg House of the automotive world. And we are but your students. Although I don't know which one I am... |
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Are you a tech, or you just looking for advise? I'm a tech. It originated a while back during a spirited thread, where some folks deemed that working on cars was a piece of cake, and no tech was worth more than like ten bucks an hour or whatever, which I disagree with, so I figure I'd put some stuff together from my daily routine and let other guys walk through and find the problem. Sorry I'm a dumbass. I just noticed the diagram was off of dealerconnection |
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What is the motor's resistance/impedence, disconnected from the ABS control unit? I believe the motor may be at fault. I cannot find any resistance specifications for the motor in the service manual. Let's say that there's another known good truck that you checked the ABS pump motor's resistance on, and it's the same as our problem vehicle. |
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Are you a tech, or you just looking for advise? I'm a tech. It originated a while back during a spirited thread, where some folks deemed that working on cars was a piece of cake, and no tech was worth more than like ten bucks an hour or whatever, which I disagree with, so I figure I'd put some stuff together from my daily routine and let other guys walk through and find the problem. Sorry I'm a dumbass. I just noticed the diagram was off of dealerconnection No problem. You a Ford guy? |
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Quoted: Quoted: Are you a tech, or you just looking for advise? I'm a tech. It originated a while back during a spirited thread, where some folks deemed that working on cars was a piece of cake, and no tech was worth more than like ten bucks an hour or whatever, which I disagree with, so I figure I'd put some stuff together from my daily routine and let other guys walk through and find the problem. That may have been how it started and what motivated it originally, but it's now elevated to my favorite arfcom threads. I look forward to each and everyone of these. I hope nobody answers it until I've sobered up tommorow. |
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ETA - Any Ford techs who've dealt with Ford technical assistance probably knows what tool I'm talking about. I only work on GM's so i dunno what tool you are talking about |
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Well, then, if it isn't power or motor and all wheel sensors are working, then it must be the controller.
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ETA - Any Ford techs who've dealt with Ford technical assistance probably knows what tool I'm talking about. I only work on GM's so i dunno what tool you are talking about You've got way more patience than I do, working with GM stuff. I've dealt with Trail Blazers from time to time, I think I'm scarred for life on 'em. |
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Crimped brakeline causing a sensor to go apeshit and not see sufficient pump pressure ?
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Well, then, if it isn't power or motor and all wheel sensors are working, then it must be the controller. Okay. You replaced the ABS module, and the code returned. Now what? |
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Crimped brakeline causing a sensor to go apeshit and not see sufficient pump pressure ? No faults were found with the service brake system. The service brakes stop the truck straight and true, but the ABS is inop. |
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ETA - Any Ford techs who've dealt with Ford technical assistance probably knows what tool I'm talking about. I only work on GM's so i dunno what tool you are talking about You've got way more patience than I do, working with GM stuff. I've dealt with Trail Blazers from time to time, I think I'm scarred for life on 'em. GM's are not that bad.. They do some stupid shit from time to time but so does everyone elese |
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ETA - Any Ford techs who've dealt with Ford technical assistance probably knows what tool I'm talking about. I only work on GM's so i dunno what tool you are talking about You've got way more patience than I do, working with GM stuff. I've dealt with Trail Blazers from time to time, I think I'm scarred for life on 'em. GM's are not that bad.. They do some stupid shit from time to time but so does everyone elese Yeah, they ain't too bad for someone who deals with them on a daily basis. I can futz and fight my way through one, but I still look like a monkey humping a football, ya know? It's different when you work on a particular brand/model day in and day out. |
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ETA - Any Ford techs who've dealt with Ford technical assistance probably knows what tool I'm talking about. I only work on GM's so i dunno what tool you are talking about You've got way more patience than I do, working with GM stuff. I've dealt with Trail Blazers from time to time, I think I'm scarred for life on 'em. GM's are not that bad.. They do some stupid shit from time to time but so does everyone elese Yeah, they ain't too bad for someone who deals with them on a daily basis. I can futz and fight my way through one, but I still look like a monkey humping a football, ya know? It's different when you work on a particular brand/model day in and day out. Thats the way I look at Fords |
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Voltage drop across all wires? are all the ground s good? Voltage drop at the ABS pump shows no drop (after all, the pump ain't running), and you've verified ground G101 for the ABS module is good. Just for the hell of it, we overlaid G101 to double check it, no change. |
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Must be electrical connections. Any corrosion/dirt? A visual inspection of the various connectors throughout the system shows no obvious faults. |
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With no other information I would check the battery voltage inputs to the ABS control unit, and the grounds. But from what I can tell there are no grounds in that schematic!
Any chance you can make the image a little bigger? Holy crap, when I first clicked on this there were no other posts. Got caught up reading something else, came back to it and there's a bunch of replies. |
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With no other information I would check the battery voltage inputs to the ABS control unit, and the grounds. But from what I can tell there are no grounds in that schematic! The grounds are on the lower left hand side of the diagram, and both checked okay. They were overlaid and rechecked, no change. The power circuits (circuit 640, 601, 534, and 483) were all tested with a volt meter and show battery voltage where appropriate. |
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The tool is black electrical tape.......To cover up the idiot light on the dash.....Fucking computers!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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Another tech in the shop loaned you a tool to check this truck out. http://i32.photobucket.com/albums/d1/DBNissan/Tech/0cb56322.jpg It's got a 3157 bulb in it. What does the repair manual say about this tool? Some of us are not FoMoCo trained...it has been 8 years since I've touched one |
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The tool is black electrical tape.......To cover up the idiot light on the dash.....Fucking computers!!!!!!!!!!!!!!!!!!!!!!!!!!!! Electrical tape over the light, taking the bulb out of the instrument cluster, cutting wires to the cluster, all not an option for fixing this truck. |
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Is the motor siezed ? is it a brushless motor ? Well, I dunno. Let's apply power and ground from the battery directly to the motor and see. Huzzah - the motor runs. So, we know the ABS pump isn't at fault. But yet, we have power and ground to the pump. Hmmm... |
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Is the motor siezed ? is it a brushless motor ? Two wires? Not a brushless. Single speed brush type. |
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Is that lamp holder being used instead of a test light or is the a reason to use a 3157 lamp?
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Another tech in the shop loaned you a tool to check this truck out. http://i32.photobucket.com/albums/d1/DBNissan/Tech/0cb56322.jpg It's got a 3157 bulb in it. What does the repair manual say about this tool? Some of us are not FoMoCo trained...it has been 8 years since I've touched one This is a field expedient tool, not mentioned in the service manual. |
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Is the motor siezed ? is it a brushless motor ? Well, I dunno. Let's apply power and ground from the battery directly to the motor and see. Huzzah - the motor runs. So, we know the ABS pump isn't at fault. But yet, we have power and ground to the pump. Hmmm... power and ground, but no signal. right? |
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Is that lamp holder being used instead of a test light or is the a reason to use a 3157 lamp? Well, a 3157 bulb draws more current than the rinky dink bulb in a test light, so it could most certainly be used as a test light, and it's rigged up as such. Now, where are we testing? |
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I always start with the simplest explanation , the fuses , then I check the pump to see if it's actually working , work backward from there . Is there a maintenence switch in the circut ? I know there was a 3 position switch on one car I worked on , the light would come on at certain intervals and wouldn't go out till the mechanic (me) inspected the system and flipped the switch hidden up under the dash . older BMW's had a little rig the mechanic had to reset the computer with . Anything like that going on here perhaps ? Okay. You checked and verified, fuses 6 and 28 in the battery junction box are not open and there is power at them, likewise with fuses 11 and 14 at the central junction box. In the scan tool, there is a test called active commands, where we can use the scan tool to command the ABS pump on. Doing this, the pump does not run. There's no switches or electrical trickery here either. Connect a bulb and socket across the output of the controller going to the motor and command the pump on, if the bulb lights, the pump is bad, if the bulb does not light, the controller is bad. |
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Is the motor siezed ? is it a brushless motor ? Well, I dunno. Let's apply power and ground from the battery directly to the motor and see. Huzzah - the motor runs. So, we know the ABS pump isn't at fault. But yet, we have power and ground to the pump. Hmmm... power and ground, but no signal. right? By signal, do you mean a signal from the module to turn the pump on? If so, yes, when the pump is commanded on with the scan tool, we can see that there is power and ground available at the pump. So, the module is working correctly. |
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